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I've been working on my FWRR for the past year, attempting to persuade the fire not to go out when the smokebox is shut.  She steams beautifully as long as it is open a crack.

I have printed all the threads here - thanks to Dave H. and others who have given freely of their time and energy.  The stainless burner mesh makes the fire behave quietly, but as soon as you close the door and start moving, a big globule of oil/water pops out of the chuff pipe and seems to block the airflow around the smokebox.  The chimney is only 1/4" diameter, but it is quite long so I am reluctant to try to drill it out!



The apparent next step is to open up the hole in the bottom of the smokebox to improve the airflow - but I ran into a snag:



This photo shows the smokebox has a big hole (green arrow marks the perimeter) but there's a big chunk of saddle casting blocking the hole (red arrow.)

I may try a longer chuff pipe, with the end bent to deposit oil/water on the side of the chimney where it opens out, with the hope that the globule will disperse and not block the pipe when it runs down into the smokebox.  [There's a lovely 'crack' and a puff of blue smoke when it does - just like the 2-cyl Mitch-Cal Shay.]

Perhaps my best solution will be a more drastic approach - install a better lubricator with a valve to control oil flow.  Anyone have any other suggestions?
 

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Pete,

I change out all my Accucraft lubricators with Roundhouse Engineering ones. The Accucraft feeds way too much oil and the engines become gummy messes. I cut off the Accucraft fittings and spice them on to the Roundhouse lubricators by silver soldering and using a piece of brass 1/4" rod drilled thru as a splice.

The other change I make is to open up the air hole in the bottom of the smokebox. I understand that your opening is mainly blocked by the saddle. Any room in front at all to open up a hole? A small amount makes a big change. When I do this I don't need to open up the smokebox door to light up. I light up thru the open hole on the bottom.

Mike McCormack
Hudson, Massachusetts
 

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I had the same problem with mine. Lengthening the exhaust pipe and once around the track with a rubber tube extension over that pipe to re-direct the condensate, engine runs like a charm.
 

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Pete - On my old ruby I took the chuff pipe and cut it off just below the nut for the stack. I left it open and any oil water can spray out the stack but it isnt much. I have had no issues ever since that and think it could help you problem. I also bend it in an S shape to center it in the hold for the stack. The stack that I installed also has a small hole since it was an electric Accucraft stack from the legend 4-4-0 I think. You may also want to check that you dont have the larger jet from the factory, I did have another ruby that gave me al lsorts of burner troubles that had the larger jet from the factory by accident?????Maybe..... I installed a new jet of the smaller orfice and it lit without a hitch. That didnt burn good either since it was puttin gin too much gas and not enough oxygen.
 

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Sounds like you have 2 problems: 1) slugs of water/oil hit the sides of the smokestack, flash to steam/smoke and snuff the fire. 2) Insufficient air to sustain fire due to combustion byproducts building up in the smokebox.

I solve 1) by cutting off the crimp in the exhaust line, allowing the water/oil slugs to shoot out the stack.

I solve 2) by cleaning the gas jet: A tiny bit of debri, often too small to see with the naked eye, will affect the squirt of gas out the nozzle, making it a non circular pattern. This non-circular pattern of gas will not entrain oxygen the way it's meant to, thus forcing the burner to receive a rich mixture. The rich mixture will not burn unless it can get extra oxygen from backflow from the smokebox. If the smokebox is filled with combustion products like CO2 and CO, then the backflow won't provide sufficient oxygen to overcome the rich mixture delivered to the burner by the dirty jet. So, you can either open the smokebox door, to give another path for the combustion products to escape and the fresh air to enter, or you can open up the holes in the bottom of the smokebox to ditto, or you can clean the jet to stop the too-rich mixture in the first place.

It often helps my locos to run the first few laps with the smokebox door open a bit. After the unit heats up, I can then close the door; perhaps the cold metal inhibits the flow of combustion byproducts out the stack, just as a cold house chimney will impede the flow of fireplace smoke out the chimney.
 

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Discussion Starter #6
Well, thanks guys. Ray suggests lengthening the exhaust/chuff pipe, which I figured might help. Jason suggests shortening it - which also sounds like it will help! I guess I'll have to cut it and make up a couple of extensions: the long and the short. Now where did I put my silver solder....
 

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I don't solder the extentions I add to an exhaust pipe. I just slide a slightly bigger diameter brass pipe over the original (possibly trimmed) copper pipe. My locos all seem to have a air hole cut in the smokebox under or near the base of the exhaust pipe. Thus, any priming water or oil that does not get shot out the stack will simply slide down the brass pipe interior and fall to the track. Or, once the pipe gets good and hot, the water flashes to steam, but the pipe generally constrains it and keeps the steam from backflowing into the flue to snuff the fire.
 

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Discussion Starter #8
Brooks,

It's not snuffing the fire directly, I think.  Concensus seems to be that the Rubys need air flow through the smokebox - this particular model has a long narrow stack and a big cylinder saddle, so the large oil/water globule seems to plop out of the exhaust and block the chinmey effect.  The lack of a hole at the bottom seems to make it worse.

I've asked Cliff at Accucraft to send me a spare pipe so I can experiment with longer and shorter pipes...
 
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I was having the same problem with the firebox door.  One day while I building up steam I tried a high-tech experiment. I held a smokeing match at the slightly open door to see if this thing was starving for air. It wasn't. The smoke blew away from the opening. The flue pipe or "smoke stack" is too small to handle the heat in the burner and pressure builds up and blows the flame out. 

I'm not ready just yet to mess with the stack so I removed the fake lugs and bolts on the firebox door and drilled the bolt holes out to 1/16.  Wala. I now run with my door closed. I have a 3/4 inch sleeve over the end of the burnner so the flame stays out of the firebox. I'm a happy steamer.  .......... Ray
 

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Discussion Starter #10
Ray - interesting stuff. I'll have to experiment with that approach.

When you say 'firebox door', do you mean the smokebox?  [Firebox is usually at the other end where the coal goes in.]
 
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Opps! You have found me out. I am a greenhorn with this new hobby of mine. Yes, it is the smokebox door. I checked the cost of replaceing the door before I drilled the holes and went for the temporary modification. For 22 yrs. I have been in the heating and cooling business and this burner problem has made a monkey out of me. I don't yet have the problem solved but at least for now it is under control. ... My brother put this kit together, got frustrated and gave it to me. I have had a ball reversing the gasket he installed backwards, reversing the timing to get it to run forwards and I love the burner challenge. .... Now, had I bought my Ruby, I would be some kind of mad. I really enjoy it though and I now believe I am hooked on steam. ...... Ray
 

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Discussion Starter #12
The FWRR problems reached the top of the workshop queue today, so I started to think about how I was going to get a better out-draft.  I couldn't see any way of making holes in the smokebox door without them being very obtrusive.

One possibility was to cut the chuff/exhaust pipe so that the globs of oily water don't block the stack.  I removed the stack and took a look at it - 5/16 ID and 9/16 OD, making 1/8" thick walls.  I could definitely see drilling that out to 7/16, but I don't have a lathe and it is a bit long.  I thought of chopping the top and bottom flange off, drilling them out and re-connecting them with a thin-walled tube.  A little experimenting and I found that 15/16th brass tube will just fit through the hole in the smokebox where the stack goes, so a new stack from tube became an option.

I recalled I have a stack made up for a 'big hauler' bash which might work - but I also have a nice turned tapered brass stack from Trackside Details.  So with bits from the former, I made up (silver soldered) a new stack:



This one is 7/16" ID, about what the drilled stack would be.  So I'll try this and see how I like the look of it...  what do you think?



I guess it will look nicer with a coat of hi-temp black!  The loco's back is off as it is getting r/c next.
 

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Discussion Starter #15
Posted By Dwight Ennis on 03/22/2008 8:31 PM
Pete - the Ft. Wilderness locos seem to share this problem. What about cutting a notch in the bottom of the smokebox forward of the saddle? A thin notch made, say, with a Dremel cutoff wheel shouldn't be too noticeable, and would allow pressure to escape (if that's the problem). Just a thought.


Dwight,

Nice idea, but unfortunately the smokebox door is mounted in a ring of brass 5/16" thick (being the front of the smokebox) ! :confused: The smokebox saddle on top of the cylinders extends almost to the front - there's probably 1/16" behind the door ring before the saddle starts. /DesktopModules/NTForums/themes/mls/emoticons/angry.gif

But it's a thought.  The smokebox front could be cut back at the bottom and a hole cut in the floor.  I'll try that if this new stack doesn't solve the whole problem. /DesktopModules/NTForums/themes/mls/emoticons/unsure.gif
 
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2 cents worth:

Just for grins and giggles, last night, I removed my stack leaving just the chuff/exaust pipe sticking up. Not much for looks. I then removed the 3/4 inch long sleeve that is on my burner. I fired it off and closed the door. The flame poped back to the burner and I had steam in just a few min. Cool! Ok, well then, I need a larger dia. stack.

I have to look at this as though it were a furnace I would be working on. Not much difference really. The flue pipe, "smoke stack" must be able to handle the btu's the burner is putting out. With the sleeve on my burner, (decreased btu's), I am getting by with a "holey" smokebox door and the existing stack. I remove the sleeve, (increased btu's), and I had to remove the stack for this system to vent.

If I have a Rheem, 75,000 btu furnace and decide to make a 100,000 btu furnace out of it, (I would never do that) but if I did and assuming the the furnace is gas and naturally aspirated (oh how I love that phrase), I would not be able to leave the existing flue pipe. It would not be large enough. But, I would never ever cut a hole in the bottom of the furnace to help the system vent. I have to believe that the opening in the bottom of the "smokebox" is for drainage of condensate and was never designed to help the system vent.

With all the various modefications being done to the Ruby burners, equil time my have to be given to the flue, (stack) size. I can see how the different size jets being used on the Rubys would influence the need to run with the smokebox door open. I have no idea what size jet I have because it is not stamped with any number. That's goofy. I called called Accucraft for a replacement and what they sent me was way too big so I still use the original whaterver size it is. I am watching to see how Petes new stack works out.
 

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With a coat of flat black hi-temp, it sort of reminds me of Sir Topham Hatt ? /DesktopModules/NTForums/themes/mls/emoticons/sad.gif



Ina ny case, us Brits aren't big fans of spark arresters, so I reckon I could get used to this new look.  /DesktopModules/NTForums/themes/mls/emoticons/laugh.gif
 
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My Ruby's condensate trap.

To keep the condensate water and oil from putting out my fire, I made and installed a trap. I love the steam and smoke comeing out of the stack and so I didn't want to lose that effect by dumping the water down on the track. I had also hoped the size of the trap would catch most of the water on take-off. I'm judgeing it catches about 70%.

I have run it about 4 times just as you see in the photo and the fire has never gone out. There is enough heat in the smokebox to turn the condensate back to steam and burn the oil. While I was fitting my new stack on the box last night, I had to remove the trap for working room. I had been a little concerned about the burned oil in the tank but it was clean.

I used two tube caps for the tank. I used about one inch of the threaded end of the exaust pipe that comes on the Ruby. I used 1/4 inch tubing out of the top. I am working on my new stack.

I am pleased so far with the results of this trap. I have more smoke and steam out of the stack. The only down side to this thing is the smell of burnt steam oil. I think my next trap will have the inlet tub extend almost to the top of the tank.



 
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Opps, well sirs, I do apologize for that intrusion and I am sure I should have known better, but this is all too much for me. I'm outa here.
 
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